Mechanism underlying potentiation by progesterone of the kainate-induced current in cultured neurons.
The effect of the neurosteroid progesterone on the kainate receptor-mediated response was studied in cultured chick spinal cord neurons using the whole-cell voltage-clamp recording technique. Progesterone rapidly and reversibly potentiates the kainate-induced current in a dose-dependent manner, with an EC50 of 35 microM and a maximal potentiation of 30%. Potentiation of the kainate response by extracellularly applied progesterone is not significantly affected by inclusion of a saturating concentration of progesterone in the electrode buffer, indicating that progesterone acts at the extracellular surface of the membrane. Furthermore, progesterone enhances the kainate maximal response with little effect on the kainate EC50.
Wu
F S
FS
Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan. fongsen@mail.ncku.edu.tw
Yu
H M
HM
Tsai
J J
JJ
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D004357:Drug Synergism; D007608:Kainic Acid / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D011374:Progesterone / Q000494:pharmacology*
D011374:Progesterone; D007608:Kainic Acid